Auto merge of #77317 - varkor:break-diverging-value, r=nikomatsakis

Fix control flow check for breaking with diverging values

Fixes https://github.com/rust-lang/rust/issues/77156.

2 files changed, 56 insertions, 0 deletions

diff --git a/src/test/ui/break-diverging-value.rs b/src/test/ui/break-diverging-value.rs
new file mode 100644
index 00000000000..d070fddaffc
--- /dev/null
+++ b/src/test/ui/break-diverging-value.rs
@@ -0,0 +1,37 @@
+#![feature(never_type)]
+
+fn loop_break_return() -> i32 {
+    let loop_value = loop { break return 0 }; // ok
+}
+
+fn loop_break_loop() -> i32 {
+    let loop_value = loop { break loop {} }; // ok
+}
+
+fn loop_break_break() -> i32 { //~ ERROR mismatched types
+    let loop_value = loop { break break };
+}
+
+fn loop_break_return_2() -> i32 {
+    let loop_value = loop { break { return 0; () } }; // ok
+}
+
+enum Void {}
+
+fn get_void() -> Void {
+    panic!()
+}
+
+fn loop_break_void() -> i32 { //~ ERROR mismatched types
+    let loop_value = loop { break get_void() };
+}
+
+fn get_never() -> ! {
+    panic!()
+}
+
+fn loop_break_never() -> i32 {
+    let loop_value = loop { break get_never() }; // ok
+}
+
+fn main() {}
diff --git a/src/test/ui/break-diverging-value.stderr b/src/test/ui/break-diverging-value.stderr
new file mode 100644
index 00000000000..69edcd24080
--- /dev/null
+++ b/src/test/ui/break-diverging-value.stderr
@@ -0,0 +1,19 @@
+error[E0308]: mismatched types
+  --> $DIR/break-diverging-value.rs:11:26
+   |
+LL | fn loop_break_break() -> i32 {
+   |    ----------------      ^^^ expected `i32`, found `()`
+   |    |
+   |    implicitly returns `()` as its body has no tail or `return` expression
+
+error[E0308]: mismatched types
+  --> $DIR/break-diverging-value.rs:25:25
+   |
+LL | fn loop_break_void() -> i32 {
+   |    ---------------      ^^^ expected `i32`, found `()`
+   |    |
+   |    implicitly returns `()` as its body has no tail or `return` expression
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.